Fluid-pressure brake.



W. V. TURNER.

FLUID PRESSURE BRAKE. APPLICATlON mm on. 2. 1911.

Patented A r. 20, 1915.

VIII/14;? A

mam? INVENTOR THE NORRIS PETERS CO, PHOTO-LITHO.:WASH|NG1UN, D C

WALTER V. TURNER, 01E EDGEWOOD,

HOUSE AIR BRAKE COMPANY, OF OI! PENNSYLVANIA.

PENNSYLVANIA, ASSIGNOR TO THE WESTING- PITTSIBUBGI-I, PENNSYLVANIA, A CORPORATION FLUID-PRESSURE BRAKE.

Application filed October 2, 1911.

To all whom it may concern:

Be it known that I, WALTER V. TURNER, a citizen of the United States, residing at Edgewood, in the county of Allegheny and State of Pennsylvania, have invented new and useful Improvements in Fluid-Pressure Brakes, of which the following is a specification.

This invention relates to fluid pressure brakes, and more particularly to an apparatus for maintaining the train pipe pressure while the brakes remain applied.

With the present standard automatic air brake system, when the brakes are applied by making a reduction in train pipe pressure in the usual way and the engineers brake valve is then placed in lap position, there is no means for supplying fluid to the train pipe to maintain the pressure therein in case of leakage. It has therefore been proposed to provide means for maintaining the train pipe pressure While the brakes remain applied to thereby compensate for any leakage which may occur from the train pipe. Where an apparatus is employed for maintaining the train pipe pressure, however, it may sometimes happen that the maintaining device will leak or stick in its open position, so that the train pipe pressure is liable to be increased above the degree at which it is intended to maintain the train pipe pressure and as a consequence it may be diihcult to again apply the brakes or the brakes may even be released by the increase in train pipe pressure at atime when it is desired to hold the brakes applied.

Ihe principal object of my invention is therefore to provide means for preventing the train pipe pressure maintaining device rom increasing the train pipe pressure above the degree at which the train pipe pressure is to be maintained. For this pur pose, I preferably provide a valve device operating upon an increase in train pipe pressure above the maintaining degree for cutting the train pipe pressure maintaining device out of action.

In the accompanying drawing; Figure 1 is a diagrammatic view of a standard Nestinghouse automatic air brake equipment for a locomotive provided with a train pipe pressure maintaining device having my improvement applied thereto; Fig. 2 a central sectional view of a portion of the engineers brake valve employed in the construction Specification of Letters Patent.

Patented Apr. 20 1915. Serial No. 652,326.

shown in Fig. 1; Fig. 3 a plan view of the rotary valve seat of the engineers brake valve; Fig. 4 a face View of the rotary valve; Fig. 5 a central sectional view of a slightly modified form of cut out valve mechanism; and Fig. 6 a similar view, in part, of another slightly modified form of cut out valve mechanism.

As shown in Fig. 1, the engine air brake apparatus may be similar to that shown in my prior Patent No. 834,312, dated Oct. 30, 1906, although my improvement may be applied in connection with various forms of train pipe pressure maintaining devices. According to the above construction, the engineers brake valve 1 may be of the standard construction except as to certain additional features hereinafter more fully described and comprises a rotary valve seat 2 having the usual ports, as follows: port 3, leading to the train pipe 4; port 5, leading to the exhaust; port 6, the preliminary exhaust port, leading to chamber 7 above the equalizing piston 8; feed port 9, leading to the feed valve device 10; cavity 11, and equalizing port 12, leading to chamber 7. In addition to these ports I provide a port 13, located near the preliminary discharge port 6 and connected to the port 1 1, which leads from chamber 7 to pipe 15, communicating with the regulating chamber 16 of the regulating valve device 17. Port 14 is controlled by a small slide valve 18 operated by the movable abutment or equalizing piston 8, which also operates the equalizing discharge valve 19 in the usual way. Chamber 7 communicates through a port 20 and pipe 21 with the equalizing reservoir 22.

As shown in Fig. 4, the rotary valve 23 of the engineers brake valve 1 is provided with the usual ports 24 and 25, cavity 26, groove 27, and an additional cavity 28, adapted to connect ports 6 and 13 in the valve seat 2 when the valve is placed in running position. The regulating valve device 17 comprises a casing containing two chambers 16 and 29, separated by a diaphragm 30, the stem of which carries the regulating valve 31, which controls the flow of air from the main reservoir pipe 32 through pipe 33 and chamber 29 to pipe 34, leading to the train pipe 1. The volume of the regulating chamber 16 may be enlarged by the addition of a reservoir 35, interposed in the pipe 15, so as to render the pressure in said chamber less sensitive to slight fluctuations in pressure.

According to my improvement, a valve device 37 is interposed in the pipe 34 leading from chamber 29 to the train pipe 4, comprising a casing having a piston chamber 38 containing a piston 39 subject on one side to the pressure of the equalizing reservoir 22 supplied through the pipe 40 and the pressure of a light spring 41 and on the opposite side to the pressure of valve chamber 42 which contains a slide valve 43 adapted to be operated by the piston 39. The slide valve 43 controls communication through pipe 34 from the chamber 29 to the train pipe 4.

In operation, the train pipe being charged with fluid under pressure and the rotary valve placed in running position, compressed air from the main reservoir pipe 32 is supplied, through ports 25 and 9, to the feed valve device 10 and thence to the train pipe and the equalizing reservoir in the usual way. At the same time, the ports 6 and 13 are connected by the cavity 28 in the rotary valve, so that the equalizing reservoir chamber 7 is in communication with the regulating chamber 16 through pipe 15, thereby maintaining the pressures in the train pipe and regulating chamber equal. Upon reducing the train pipe pressure to effect a service application of the brakes, the rotary valve 23 is turned so that cavity 27 conmeets the preliminary discharge port 6, but not the port 13, with exhaust port 5, thus reducing the pressure in the equalizing reservoir 22 and causing the upward movement of the equalizing piston 8 and the discharge valve 19 in theusual manner. At the same time that the piston 8 rises, to open the valve 19, it also'moves the slide valve 18 to open the port 14, so that the regulating chamber 16 then communicates with the equalizing reservoir, and the pressure therein is reduced at the same time and to the same degree as that of the equalizing reservoir, the rotary valve being turned to lap position with all the ports closed when the desired amount of reduction has been made in the equalizing reservoir. When the discharge valve 19 closes, the valve 18 is also closed, and the air under pressure in the regulating chamber 16 is thereby sealed up at the same degree of pressure as that of the train pipe at the time the discharge valve closes. This pressure, therefore, is held constant in chamber 16 on the diaphragm 30, so that any leakage of the train pipe pressure which acts on the under side of the diaphragm will cause the opening of the regulating valve 31, thereby admitting fluid from the main reservoir through pipe 34 to the train pipe4 sufficient to compensate for any leakage and maintain the train pipe pressure constant while the brakes remain applied and with the brake valve in lap position.

lhe above operation corresponds with that of the construction covered in the hereinbefore mentioned Patent No. 884,342, but according to my present improvement, the valve device 37 is interposed in the pipe 34 through which air is supplied by the regulating device to the train pipe. Normally, the train pipe pressure acting on the inner face of the piston 39 is equal to or slightly less than the pressure of the equalizing reservoir acting on the outer face of said piston, so that the piston is normally maintained in its inner position, with the valve 43 in a position opening communication through the pipe 34 to the train pipe 4 and consequently, when the regulating valve device 17 is operating normally to maintain the train pipe pressure, the valve device 37 has no effect on the operation, but if the train pipe pressure is increased above the pressure held in the equalizing reservoir, by leakage past the regulating valve 31 or by said valve sticking in its open position, then the higher train pipe pressure thus produced causes the piston 89 to move outwardly and shift the slide valve 43 to close communication through pipe 34. It will thus be evident that the regulating valve device is cut out of action or prevented from feeding air to the train pipe above the degree of pressure held in the equalizing reservoir at that time, and consequently, when it is desired to effect an application of the brakes, the train pipe pressure may be readily reduced in the usual manner by venting air from the equalizing reservoir through the operation of the engineers brake valve, while if the regulating valve mechanism should stick when the engineers brake valve is in lap position, the action of the cut out valve mechanism in closing the feed connection from the regulating valve mechanism to the train pipe insures that the usual movement of the engineers brake valve to cause a further application of the brakes will be effective.

In addition to cutting off the communication for supplying fluid to the train pipe, the cut out valve mechanism may be constructed to vent air from the train pipe and thereby indicate the defective condition of the regulating valve mechanism by automatically causing a further application of the brakes. For this purpose, as shown in Fig. 5, a cavity 45 may be provided in the slide valve 43, which is adapted in the cut out position to connect the train pipe 4 with an exhaust port 46.

If desired, another feature may be employed, as shown in Fig. 6, in which a restricted port 47 in the valve 43 is adapted to register with an exhaust port 48, so that the exhaust of air from valve chamber 42 in the out out position Warns the engineer that the regulating valve mechanism is cut out.

Having now described my invention, What I claim as new and desire to secure by Letters Patent, is

1. In a fluid pressure brake, the combination with a train pipe, of a valve mechanism for normally maintaining the train pipe pressure at a predetermined degree, and means directly controlling the flow of fluid from said valve mechanism to the train pipe and operated upon an increase in train pipe pressure for cutting off the flow of fluid from said valve mechanism to the train pipe.

2. In a fluid pressure brake, the combination With a train pipe, of a valve mechanism for normally maintaining the train pipe pressure at a predetermined degree, a pipe leading from said valve mechanism to the train pipe and a valve device in said pipe operated by an increase in train pipe pressure to a predetermined degree for closing communication through said pipe.

8. In a fluid pressure brake, the combination with a train pipe, of a regulating valve mechanism for maintaining the train pipe pressure at a predetermined degree While the brakes are applied and a valve device operated upon an increase in train pipe pressure above said predetermined degree for closing communication through which fluid is supplied by the regulating valve mechanism to the train pipe.

I. In a fluid pressure brake, the combination with a train pipe, of a regulating valve mechanism for maintaining the train pipe pressure at a predetermined degree While the bra es are applied and a valve device comprising a piston subject to train pipe pressure and a valve operated by said piston for controlling communication through Which air is supplied by the regulating valve mechanism to the train pipe, said valve de vice being operated by an increase in train pipe pressure above the predetermined degree for closing said communication.

5. In a fluid pressure brake, the combination with a train pipe, of a regulating valve mechanism comprising a valve for controlling the supply of fluid to the train pipe, a regulating chamber, and a movable abutment subject to the opposing pressures of the regulating chamber and the train pipe for operating said valve to maintain the train pipe pressure at a predetermined degree, and means subject to the opposing pressures of the train pipe and fluid at the Copies of this patent may be obtained for five cents each,

pressure of the regulating chamber for controlling communication through which air is supplied by said regulating valve mechanism to the train pipe.

6. In a fluid pressure brake, the combination With a train pipe, of a regulating valve mechanism for maintaining the pressure in the train pipe at a predetermined degree and a valve device operating upon an increase in train pipe pressure above the predetermined degree for cutting said regulating valve mechanism out of action and having means adapted in the cut-out position for venting air from the train pipe.

7. In a fluid pressure brake, the combination With a train pipe, of a regulating valve mechanism for maintaining the pressure in the train pipe at a predetermined degree and a valve device comprising a valve for controlling communication from the regulating valve device to the train pipe and a piston operated upon an increase in train pipe pressure above the predetermined degree for actuating said valve to cut off said commu nication, said valve having a cavity for connecting the train pipe to the atmosphere in the cut out position.

8. In a fluid pressure brake, the combination with a train pipe, of a regulating valve mechanism for maintaining the pressure in the train pipe at a predetermined degree and a valve device operating upon an increase in train pipe pressure above the predetermined degree for cutting said regulating valve mechanism out of action and means controlled by said valve device and adapted in the cut-out position to give Warning that the regulating valve mechanism is cut out.

9. In a fluid pressure brake, the combination With a train pipe, of a regulating valve mechanism for maintaining the pressure in the train pipe at a predetermined degree and a valve device operating upon an increase in train pipe pressure above the predetermined degree for cutting said regulating valve mechanism out of action and means controlled by said valve device and adapted in the cut-out position to establish a flow of air to Warn the operator that the regulating valve mechanism is cut out of action.

In testimony whereof I have hereunto set my hand.

WALTER V. TURNER.

VV'itnesses:

WM. M. CADY, I. L. RAFTERY.

by addressing the Commissioner of Patents,

Washington, D. C. 

